Objective To investigate the influence of different cell structures on the static and dynamic mechanical performance of porous titanium alloy scaffolds,and to provide a theoretical mechanical basis for the application of scaffolds in the repair of mandibular bone defects.Methods Porous titanium alloy scaffolds with diamond,cubic,and cross-sectional cubic cell structures were manufactured using three-dimensional printing technology.Uniaxial compression tests and ratcheting fatigue with compression load tests were conducted to analyze the static and dynamic mechanical performances of scaffolds with different cell structures.Results The elastic moduli of the diamond cell,cross-sectional cubic cell,and cubic cell scaffolds were 1.17,0.566,and 0.322 GPa,respectively,and the yield strengths were 71.8,65.1,and 31.8 MPa,respectively.After reaching the stable stage,the ratcheting strains of the cross-sectional cubic,diamond,and cubic cell scaffolds were 3.3%,4.0%,and 4.5%,respectively.The ratcheting strain increased with increasing average stress,stress amplitude,and peak holding time,and decreased with increasing loading rate.Conclusions The evaluation results of the static mechanical performance showed that the diamond cell scaffold was the best,followed by the cross-sectional cubic cell scaffold and the cubic cell scaffold.The evaluation results of the dynamic mechanical performance showed that the cross-sectional cubic cell scaffold performed the best,followed by the diamond cell scaffold,whereas the cubic cell scaffold performed the worst.The fatigue performance of the scaffold is affected by the loading conditions.These results provide new insights for scaffold construction for the repair of mandibular bone defects and provide an experimental basis for further clinical applications of this scaffold technology.

Poor oocyte quality is responsible for female infertility. The search for supplements to improve oocyte quality is receiving increasing attention. Many studies have shown that L-carnitine plays a variety of roles in regulating female fertility. This article reviews the key roles and regulatory mechanisms of L-carnitine in oocyte maturation and early embryonic development, including activating fatty acids for β-oxidation to regulate energy metabolism, antioxidation to prevent oxidative damage, and inhibition of cell apoptosis, and the research progress of LC in improving oocyte quality and early embryo development.

Poor oocyte quality is responsible for female infertility. The search for supplements to improve oocyte quality is receiving increasing attention. Many studies have shown that L-carnitine plays a variety of roles in regulating female fertility. This article reviews the key roles and regulatory mechanisms of L-carnitine in oocyte maturation and early embryonic development, including activating fatty acids for β-oxidation to regulate energy metabolism, antioxidation to prevent oxidative damage, and inhibition of cell apoptosis, and the research progress of LC in improving oocyte quality and early embryo development.

Objective:To observe the effect of methylphenidate hydrochloride (MPH) combined with mentalization-based family therapy (MBFT) on clinical efficacy and social function in children with attention deficit hyperactivity disorder (ADHD).Methods:Sixty-four children with ADHD diagnosed in Wuxi Children's Hospital and Affiliated Hospital of Jiangnan University from June 2019 to May 2021 were selected and divided into observation group ( n=32) and control group ( n=32) according to the random number table.Children in both groups received methylphenidate hydrochloride extended-release tablets, while those in the observation group were given additional MBFT.The duration of treatment was 12 weeks in both groups.The parent symptom questionnaire (PSQ), swanson nolan and pelham-version Ⅳ (SNAP-Ⅳ) parent Al scale, and Weiss impairment functional scale (WFIRS-P) were used to evaluate the effectiveness of treatment.Statistical analysis was performed by SPSS 25.0 statistical software.In particular, the χ2 test was used for counting data and the paired sample t test was used for comparison of measurement data between the two groups before and after treatment. Results:(1) All the PSQ dimension scores of patients in the observation group and the control group after treatment were significantly lower than those before treatment (all P<0.01). Compared with the control group after treatment, the PSQ dimension scores of personality and behavior problems ((1.25±0.15), (0.94±0.18), t=7.484, P<0.001), learning problems ((1.57±0.16), (1.32±0.20), t=5.522, P<0.001), psychosomatic disorders ((0.56±0.11), (0.44±0.13), t=3.986, P<0.001), impulse hyperactivity ((1.76±0.23), (1.54±0.25), t=3.663, P<0.001), anxiety ((0.94±0.12), (0.76±0.11), t=6.255, P<0.001) and hyperactivity index ((1.74±0.19), (1.51±0.16), t=5.238, P<0.001) decreased significantly in the observation group after treatment.(2) Compared with the pre-treatment period, the SNAP-Ⅳ scale scores of attention deficit, impulsivity-hyperactivity and oppositional defiance were significantly lower in both groups after treatment (all P<0.01); and compared with the control group, the SNAP-Ⅳ scale scores of the above three dimensions were significantly lower in the observation group (all P<0.01). (3) All six dimensions (family, learning and school, life skills, self-management, social activities, and risk-taking activities)of the WFIRS-P scale were significantly lower in the children in the observation group after treatment compared with those before treatment (all P<0.01), and all the six dimensions of the WFIRS-P scale were significantly lower in the observation group compared with those in the control group (all P<0.01). Conclusion:Methylphenidate hydrochloride extended-release tablets combined with MBFT can significantly improve the clinical symptoms and social function of children with ADHD.

Natural degeneration or trauma of articular cartilage all can lead to its structural and functional damage. Without blood supply and nerve innervation, chondrocytes in the matrix lacunae obtain essential nutrients and excrete metabolites mainly through osmosis, finally leads to its low metabolic activity and difficulty in self-repair after injury. At present, drug conservative treatment and surgical operation are the main clinical treatment, but both of them can't meet the clinical needs well. The development of cartilage tissue engineering provides a new direction for the repair of articular cartilage injury, in which growth factors plays a very important role. Growth factors, together with seed cells and cell scaffolds, constitute the three elements for the construction of tissue-engineered cartilage. Among them, Growth factors can significantly promote cell proliferation and differentiation and induce their functions. Various growth factors synergistically mediate the differentiation of seed cells into chondrocytes. In recent years, stem cell cartilage tissue engineering developed rapidly, which has opened a new way for repair of articular cartilage damage due to its abundant cell resources, small damage to body itself, strong ability of proliferation and directional differentiation, biological repair and other prominent advantages. Different types of hydrogels and stem cells show different abilities to support chondrogenesis and require different growth factors to induce chondrocyte differentiation. Traditional growth factors for tissue engineering include transcription growth factor β, insulin-like growth factors, bone morphogenetic proteins, fibroblast growth factors and cartilage derived morphogenetic protein. Recently, some scholars found that platelet-rich plasma, platelet-rich fibrin, Kartogenin and Mechano-growth factor can also effectively induce chondrogenic differentiation of stem cells and maintain chondrocyte phenotype. In addition, some synthetic compounds such as dexamethasone and inorganic particles can also promote the differentiation of stem cells into cartilage. This article systematically summarized the new progress of the traditional growth factors, emphatically introduced the new discovered growth factors and some synthetic compounds and inorganic particles, which can induce stem cells into cartilage. Finally classified the different sources of stem cells and its suitable growth factors, and gave an outlook of the next research direction of growth factors.

Sperm-mediated gene transfer (SMGT) is one of the most methods in the transgenic animal research and the efficiency of spermatozoa binding and internalization exogenous DNA after sperm/DNA co-culture is important to a successful SMGT.In this study,the influencing factors of exogenous DNA uptake by spermatozoa were detected using DIG labeled EGFP as exogenous gene.The results demonstrated that porcine spermatozoa could spontaneously take up exogenous DNA which mainly binding occurs on the sub-acrosomal and nuclei region of the sperm head.The rate of spermatozoa binding exogenous DNA increased with the extending action of time.At 37℃ and 39℃,the rate of spermatozoa uptake exogenous DNA would not increase after 60 min incubation,and the similar result was observed on 90 min at 17℃.Binding rates and internalization rates of washed ejaculated sperm cells from the 15 boars varied between 6.57%-35.81% and 2.990%-24.66%,respectively.The binding rate and intemalization rate were mostly inhibited by seminal plasma.The binding rates were significantly increased by liposome and DMSO,respectively.Dead-spermatozoa could bind exogenous DNA,the intermalization process could not be completed.Furthermore,the highest binding rate was found in membrane broken spermatozoa as a result of freeze-thawing and this was independent of the sperm donors.